Snubber



" named ball-draulic.

Objectional features of hydraulic shock ab- Patented Apr. 21, 1942 by srmmsrm v Edward G. Glick, Hammond, 1nd,, assignor to American Steel Foundries, Chicago, 111., a corporation of New Jersey Application June 26, 1940, Serlal No. 342,459 30 Claims. (Cl. 267-34) My invention relates to shock absorbing devices and more particularly to a device operating under hydraulic principles and'utilizing a novel fluid medium: which comprises a plurality of relatively small spherical elements or pellets, such as hardened steel balls, and which I have sorbing devices utilizing a fluid medium, such as oil, are that expensive machining operations are necessary to closely fit the operating parts in ordertoreduce the escape and leakage of the parts toretain the fluid medium are unnecessary .and wherein a normally smooth cast surface is suflicient, thereby reducing manufacturing costs.

oil, and fluctuating temperature conditions,

which cause changes in the viscosity of the oil, afiect theircapacity and consistency of performance.-v My invention contemplates designing a device shown in Figure 1 without the fluid mesnubbing device of hydraulic type wherein the above-mentioned, obiectional features are substantially'eliminated while the avantages of such devices-are retained. I accomplish this by using a fluid medium comprising a plurality of small hardened steelballs which behave like a heavy fluid-,andwhich, for practical purposes," follow and obey the hydraulic laws applicable thereto.

An object of my invention is to design a snubbing device of simple construction utilizing my novel fluid medium and conforming to standard manufacturing and service requirements.

My invention contemplates a snubbing device of the hydraulic ,type wherein a piston is afforded with ducts or passages therein through whic the fluid medium may flow.

Another object of my invention is to design Referring to the drawing, Figure 1 is generallya sectional view of one modification of my novel invention, a fragmentary portion of the end followers being shown in elevation, the section being taken substantially in a vertical plane bisecting the device as indicated by line l-l of Figure 2.

Figure 2 is a top plan view of the device shown in Figure 1'. Figure 3 is a fragmentary sectional view of the dium, the section being taken substantially in the horizontal plane. indicated by line 3-3 of Figure 1.

Figure 4 is a side elevation of a different 'modi fication of my invention, partly in section, the section being taken substantially. in a vertical plane bisecting the device. r

Figure 5 is a sectional view of the device shown in Figure 4 without the fluid medium, the section being taken substantially in the horizontal reciprocal movement in a chamber fllledwith my novel fluid medium, said piston having a head such a snubbing device utilizing my novel fluid medium and suitable for use in well-known spring group arrangements: on, a railway car truck.

My invention also contemplates such a'snubbing' device which may be connected between relativelymovable members, such as the side frame and bolster on a railway car truck, for snubhing the action thereof.

p A furtherobiect of my inventio'n' is to design a snubbing deviceutilizinga fluid'medium which will be substantially uninfluenced' by fluctua tions in temperature.

- M'y invention also contemplates desiging such a snubbing device wherein the piston head-is of for sudden increases in load, and easy recovery is afforded as the load is reduced.

My invention comprehends such a snubbing device wherein close fits between the operating plane indicated by line 5-'-5 of Figure 4.

Figure 6 is an enlargedfragmentary view of the device shown in Figure 1 showing in detail the manner in which the chamber 3. is sealed at its open end, only one side of the structure being shown since it' is identical at each side thereof. 1 v

Describing my novel structure in greater detail and referring first to the modification shown in Figures 1 to 3, the snubbing device generally indicated at 2 comprises a bottom-follower 4 having a circular base 6 with a slightly arcuate outer face 8 aifording convenient seating means for said device, said face being interrupted by the central recess 1 0 serving aspositioning' means for said device on a spring plank or spring seat in a railway cartru'ck in well-known manner. 0n

the inner surface of said base 6 may be seateda coil spring I: as at M and radially inward thereof. may be seated as at It on an annular shelf formed on said base, the relatively smaller. coil spring 18. The hollow centrally formedcasing or cylinder 20 on said bottom follower 4 projects Y into the coil spring 18 and receives through its a form such that maximum resistance is afforded open end for sliding engagement therewith the hollow cylinder or casing 22 centrally formed on the top iollowerll. The top follower 24 has a circular base aflording seats on its inner surfaces for the coil springs l2 and I8 as at 2B and 28 respectively substantially similar to the seats afforded on the bottom follower. The slightly balldraulic fluid and it is understood, of course,

that said chamber will be completely filled when the device is operated. The piston rod 36 extends into said chamber 34 and on its upper end may be formed a piston head 38 having a fit with the inner surfaces of the chamber 34 such as may be obtained by smooth casting of said surfaces.

The piston head 38 may be formed with a flat outer face 40 and its inner face may be tapered as at 42, said outer face 40 affording maximum resistance to the fluid medium when the device is compressed under load and said tapered inner face affording easy recovery of the device as the load is decreased. Ducts or passages 44, 44 may be spaced around the outer circumference of said piston head, the size, number, and shape of said ducts being determined by the dampening characteristics desired in said device and are shown here as being substantially rectangular in shape. It may be noted that once the type .and size of these ducts in the periphery of the piston are determined for the desired dampening characteristics, new snubbing devices may be made with uniform dampening action and further calibration is unnecessary. A screw 46 having an elongated head may be centrally threaded into said piston head and at its opposite end has sliding engagement with the hole 48 centrally formed in the base portion of the cylinder 22, said screw serving as guiding means and steadying means for the piston 36. A washer 49 is afforded around the head of said screw at its entrance into the hole 48.

Sealing means for the open end of the chamber 34 comprises a flanged sleeve 60 around said piston rod 36 adjacent the open end of the cylinder 22 and having annular engagement with the inner surfaces of the chamber 34. A ring 52 of resilient material may be compressed between said sleeve and the ring washer 54, clearance as at 56 being allowed between the lower end of the sleeve and said washer 54 to permit the takingup of lost motion in the device by the resilient ring 52. The outer annular edge 58 of the cylinder 22 maybe bent radially inward in any convenient manner to retain said washer and sleeve in position.

The piston rod 36 has a bearing collar 60abutting the inner surface of the base of the cylinder and extends therethrough for threaded engagement with the nut 62 received in a central recess 64 formed above the positioning recess I0.

In operation as the device is compressed, the cylinder 22 slides downwardly within the cylinder 20 and the ball-draulic fluid in the upper part of the displacement chamber 34 is forced through'the' ducts and passages in the piston head into the lower portions of said chamber. As the load is released, the coil springs return the top follower to its normal released position and the ball-draulic fluid in the lower displacement chamber is forced through the ducts in the piston head into the upper displacement chamber. It

- draulic fluid, a snubbing device of simple form should be noted that by the use of my novel balland construction is attained without expensive machining to obtain close tolerances for reducing the leakage and loss of the fluid medium.

Referring to the modification in Figures 4 and 5, an application of my novel snubbing device is shown connected between two relatively movable members, such as a side frame and a bolster in a railway car truck, although it is understood, of course, that my snubbing device may be used between any two relatively movable members. The device shown comprises an outer cylinder or casing having telescopic relationship with a cylinder 92 extending therewithin, said cylinder 92 having a hollow chamber 94 filled with my novel ball-draulic fluid medium generally indicated at 95; A cylindrical flller block 96 may be seated on a plate spring 98 at the bottom of said cylinder 92, the plate spring serving to take up lost motion. A piston rod I00 extends-into the chamber 94 and its end I02 may project into a central opening I04 in the filler block 96 to serve as guiding means for said piston. Spaced from the end I02 of the piston rod I00 may be formed a piston head I06 having an annular fit with the inner circumferential surfaces of the chamber 94 such as may be obtained by casting said surfaces smooth. The piston head I06 divides the chamber 94 into upper and lower displacement chambers, and spaced orifices or passages I08, I08 of any convenient size, number. and shape may be formed around the periphery of said head to aiford passageways for the balldraulic fluid. The piston head I06 may be tapered on opposite sides as at 0 for affording equal resistance under compression and under release. A metal ring II2 seals the open end of the cylinder 92 and after the fluid and piston head have been inserted in the chamber 94, the sealing ring II2 may be securely retained in any convenient manner, shown here as by pressing an annular groove II4 around the outer circumference of the cylinder 92 adjacent its open end so that an annular retaining flange is formed on the inner surface of the cylinder 92 in engagement as at H5 with a complementary groove on the sealing ring II2. slidingly engages the piston rod I00 and the cylinder 90, said cylinder 90 being relieved as at I I6 to afford an accurate flt with the cylinder 92. The piston rod I00 has a bearing collar I I0 in annular abutment as at I20 with the central inner surfaces of the end of the cylinder 90. Resilient mounting for the cylinder 90 on a movable member I22 may be afforded by semispherical resilient pads I 24, I 24 seated on opposite sides of said member I22 as at I26 and havingtheir semi-spherical surfaces seated in complementary recesses I28 and I30 formed respectively on the outer end of the cylinder 90 and the inner face of the cap I32. The piston rod I00 extends through the end of the cylinder 90. the resilient members I24, I24 and the cap I32 for threaded engagement with the securing lock nut I33.

The cylinder 92 is similarly resiliently mounted on a movable member I34, said resilient mounting comprising the semi-spherical resilient pads I36, I36 seated on opposite sides of said member I34 and against complementary concave surfaces I31 and I39 formed respectively on the outer end of the cylinder 92 and the inner surfaces of the cap I38. A bolt I40 having its head countersunk in the. end of the cylinder 92 extends through said end, said resilient pads I36.

The sealing ring II 2 of the device will, of course, be apparent to those skilled in the art without departing from thespirit of the invention or the scope of the claims.

I claim:

1. In a snubbing device, a plurality of coil springs, end followers affording seats for said springs, casings on each of said followers extending within said springs for sliding engagement with each other, a sealed chamber in one of saidcasings, a piston having a head with spaced pas: sageways therein and operable within said chamber, 'a medium acting as a fluid contained in said chamber and comprising a plurality of small spherical elements, said piston head being formed to afford maximum resistance to said fluid for sudden increases of loadand to ailord easy recovery when said load is released.

2. In a snubbing device, a compression spring, 3 end followers affording seats for said spring, cylinders on each of said followers sleeved within said spring for sliding engagement withv each other, a sealed chamber in one of said cylinders,

a plurality of hardened pellets immersed in oil contained in said chamber, a piston having a head adapted for. reciprocal movement within said chamber, spaced passages through said head, and resilient means at one end of said chamber for taking up lost motion in said device.

3. In a snubbing device, a compression spring, end followers affording seats for said spring, cylinders on each' of said followers sleeved within said spring for sliding engagement with each other, a sealed chamber in one of said cylinders, a plurality of hardened pellets immersed in oil contained in said chamber, and a pistonhaving a head with spaced passages therethrough reciprocally operable within said chamber, said head sistance to compression of said device and'having medium, said sliding engagement being along normally smooth cast surfaces.

6. In a shock absorbing device, inner and outer casings resiliently supported on relatively movable members and arranged for sliding engagement with each other, sealing means for the open end of one of said casings forming therewithin a chamber, resilient means within said chamber, a

plurality of small hardened steel balls immersed in a lubricant contained within said chamber, a piston having a head reciprocally operable within said chamber, and spaced orifices around the periphery of said head for the passage therethrough of said medium.

7. In a snubbing device, a compression spring, end followers affording seats for said spring,

- cylinders on each of said followers sleeved within said spring for sliding engagement with each other, a sealed chamber in one of said cylinders, a plurality of hardened pellets immersed in oil contained in said chamber, and a piston having a head with spaced passages therethrough reciprocally operable within said chamber, said head having a flat outer face affording maximum resistance to compression of said device.

8. In a snubbing device of hydraulic typ'e, inner and outer casings secured to relatively movable members and disposed in telescopic relationship, sealing means for the open end of said inner casing forming therewithin a chamber, a fil er block resiliently seated in said chamber, aplurality of hardened steel balls contained in said chamber, a piston having a head with a plurality of spaced passages therein operable within said chamber,

and guiding means for said piston engaging said filler block.

4 9. In a snubbing device of hydraulic type, inner and outer cylinders disposed in telescopic relationship and resiliently mounted on relatively movable members, sealing means for the open end of the inner cylinder-forming therewithin a displacement chamber, a piston having a head operable within said chamber, a plurality of steel pellets contained in said chamber and acting as tapered inner surfaces affording easy release as load is decreased.

4. In a snubbing device of hydraulic type, inner and outer casings disposed in telescopic relation- (ill ner casing forming therewithin a chamber, a

member resiliently seated in said chamber, a

said chamber such as obtained by smooth casting of said surfaces.

5. In a shock absorbing device ofhydraulic type, inner and outer casings disposed for sliding engagement one within the other, sealing means for one of said casings forming therewithin a chamber, a medium acting as a fluid contained in saidchamber and comprising a plurality of steel pellets, a piston having a head adapted for reciprocal sliding engagement within saidchamber, a plurality of spaced orifices in said head for the passage therethrough of said a fluid medium,-and spaced passages in said head through which the steel pellets may be displaced from one side of said head to the other thereof.

.10. In a snubbing device of hydraulic type, a pair of telescopic cylinders, sealing means for the open end of one of said cylinders affording a displacement chamber,-a medium acting as a fluid contained in said chamber and comprising a plurality of small spherical elements immersed in lubricant, a piston having a head reciprocally operable within said chamber, spaced passagesin said head for the flow therethrough of said medium, and steadying means on said piston engaging one of said cylinders.

11. In a snubbing device of hydraulic type, inner and outer casings secured to relatively movable-members and disposed in telescopic relationship. sealing means for the open end of said inplurality of hardened steel balls contained in said chamber, and a piston having ahead witha plurality of spaced passages therein operable within said chamber.

12. In a snubbing device of hydraulic type, a pair of telescopic cylinders, sealing means for the open end of one of said cylinders affording a displacement chamber, a medium acting as a fluid contained in said chamber and comprising a plurality of small spherical elements immersed in lubricant, a piston having a head reciprocally chamber, spaced orifices in said head, a medium contained in said chamber acting as a fluid and comprising a plurality of spherical elements, said head having a flat outer face affording maximum resistance to said fluid.

14. In a snubbing device, inner and outer cylinders resiliently mounted on relatively movable members, a spring in said inner cylinder, a block seated on said spring,sealing means for the'cpen end of said cylinder forming with said block a chamber, a piston having a head operable within said chamber, a plurality of passages through said head, a fluid medium contained in said chamber and comprising a plurality of small spherical elements, and means on said piston engaging said block for steadying said piston.

15. In a shock absorbing device, a plurality of coil springs, end followers affording seats therefor, cylinders on said followers intelescopic relationship and sleeved within said springs, a sealed chamber in one of said cylinders, a piston secured to one of said followers and having a head operable within said chamber, a plurality of spherical elements contained in said chamber, and spaced passages in said head affording conduits for the displacement of said spherical elements.

16. In a snubbing device of the hydraulic type, a pair of telescopic cylinders, sealing means for the end of the inner cylinder forming therewithin a chamber, a piston having a head operable within said chamber, a plurality of passages through said head, and a medium acting as a fluid contained in said chamber and comprising a head, and a fluid medium in said chamber comprising a plurality of steel balls.

21. In an energy absorbing device, relatively movable members, a casing supported on one of said members and having a chamber, a piston head supported within said chamber by the other of said members and having passages therein, and a medium acting as a fluid contained within said chamber and comprising a pluralit of metallic pellets.

22. In an energy absorbingdevice, relatively movable members, a casing supported on one of said members and having a chamber, a piston having a head supported within said chamber by the other of said members and having passages therein, a medium acting as a fluid contained within said chamber and comprising a plurality of metallic balls, and guide means in said casing for said piston.

23. In an energy absorbing device, relatively movable members, a casing supported on one of said members and having a chamber, a piston head supported within said chamber by the other of saidmembers and having passages therein, and a medium acting as a fluid contained within said chamber and comprising a plurality of metallic pellets, said piston head being tapered on opposite faces.

plurality of steel pellets immersed in a lubricant.

17. In a snubbing device of the hydraulic type, a pair of telescopic cylinders, sealing means for the end of the inner cylinder forming therewithin a chamber, a piston having a head operable within said chamber, a plurality of passages through said head, and a medium acting as a fluid contained in said chamber and comprising a plurality of small spherical elements immersed in grease.

18. In a snubbing device of the hydraulic type. a pair of telescopic cylinders, sealing means for the end of the inner cylinder forming therewithin a chamber, a piston having a head operable within said chamber, a plurality of passages through said head, and a fluid medium contained in said chamber and comprising a plurality of small spherical elements.

19. In a shock absorbing device, inner and outer casings disposed for sliding engagement with each other and secured to relatively movable members, a sealed chamber in said inner cylinder, a piston head operable within said chamber, spaced passages in said head, and a fluid medium contained in saidchamber comprising a plurality of hardened steel balls.

20. In a snubbing device, a plurality of coil springs, end followers affording seats for said springs, casings on each of said followers extending withintsaid springs for sliding engagement with each other, a sealed chamber in one of said casings, a piston head operable within said c ber, spaced passages extending through said 75 24. In an energy absorbing device, relatively movable members, a casing supported on one of said members and having a chamber, a piston head supported within said chamber by the other of said members and having passages therein, a

medium acting as a fluid contained within said chamber and comprising a plurality of metallic pellets, and resilient means in ,said chamber for reducing lost motion in said device.

25. In an energy absorbing device, telescoped casings resilientl mounted on relatively movable members, a sealed chamber in one of said casings, a piston associated with the othercasing and having a head adapted for reciprocal movement in said chamber, said head having passages therein, and a medium acting as a fluid contained in said chamber and comprising a plurality of metallic balls.

26. In an energy absorbing device, telescoped casings supported on relatively movable members, a sealed chamber in one of said casings, a piston associated with the other casing and having a head adapted for reciprocal movement in said chamber, said head having passages therein, and a medium acting as a fluid contained in said chamber and comprising a plurality of round metallic elements.

27. In a snubbing device, a compression spring, end followers affording seats .therefor and presenting casings received within said spring for sliding engagement with each other, a chamber in one of said casings, a perforated piston head associated with the other casing and operable within said chamber, and a fluid medium in said chamber including a plurality of small metallic elements.

28. In a snubbing device, a compression spring, end followers affording seats therefor and presenting casings received within said spring for sliding engagement with each other, a chamber in one of said casings, a piston associated with one of said followers and having a head operable within said chamber, a medium acting as a fluid in said chamber including small metallic elements, and passages in said head for displacement of said medium.

29. In a snubbing device, a compression spring,

end followers affording seats therefor and presenting casings received within saidspring for sliding engagement with each other, a chamber.

in one of said casings, a piston associated with i one of said followers and having ahead operable within said chamber, a medium acting as a fluid in said chamber including small metallic 1 elements, and spaced passages in the periphery of said head for displacement of said medium.

30. In' an energv absorbing device, end followers, asealed chamber on one-0t said 101- lowers, a plurality of metallic pellets contained within said chamber and acting as fluid, a piston on the other follower having a head operable in said chamber, and passages in said head for- 

